1. Technical Field
The present invention relates to an organic photoelectric conversion device having a photoelectric conversion layer formed of an organic layer and an imaging device equipped therewith.
2. Background Art
Imaging devices such as CCD sensors, CMOS sensors, and the like are known widely as image sensors used in digital still cameras, digital video cameras, cell phone cameras, endoscope cameras, and the like. These devices are equipped with a photoelectric conversion device having a light receiving layer which includes a photoelectric conversion layer.
Development of photoelectric conversion devices that use organic compounds and imaging devices using the same has been conducted by the present applicant, et al. The present applicant, at al. have filed a patent application for an organic photoelectric conversion device that uses a mixed layer (bulk hetero layer) of a p-type organic semiconductor and a fullerene or a fullerene derivative in a part of a light receiving layer with a view to improve the photoelectric conversion efficiency (sensitivity) (Japanese Unexamined Patent Publication No. 2007-123707).
According to Japanese Unexamined Patent Publication No. 2007-123707, an organic photoelectric conversion device having good photoelectric conversion efficiency (sensitivity) may be provided. Among the photoelectric conversion devices, light receiving devices used in the applications of sensors, imaging devices, and the like, the S/N ratio of photo current/dark current and response speed are important in the performance.
As a light receiving device that improves the photoelectric conversion efficiency (sensitivity) and the response speed without degrading the S/N ratio when an external voltage is applied, the present applicant, et al. have filed a patent application for an organic light receiving device which is an organic photoelectric conversion device that functions as alight emitting device (organic light emitting device) in which a charge blocking layer for preventing carrier (charge) injection from an electrode due to an external electric field is provide between the electrode and the organic photoelectric conversion layer (Japanese Unexamined Patent Publication No. 2007-088033).
Further, the present applicant, et al. have filed a patent application for an organic light receiving device that uses a layer of mixture of a fullerene or a fullerene derivative and an insulating material (Japanese Unexamined Patent Publication No. 2009-182095) or an organic light receiving device that uses a layer of mixture of a fullerene or a fullerene derivative and an electron transport material (Japanese Unexamined Patent Publication No. 2012-019235) in a hole blocking layer which is a charge blocking layer that suppresses hole injection from the electrode in the organic light receiving device of Japanese Unexamined Patent Publication No. 2007-088033 as a structure that may further provide a dark current suppressing effect.